1. Field of the Invention
The present invention relates to a side fixing frame for a liquid crystal display device, and particularly to a U-shaped side fixing frame with multiple engaging elements to couple and to secure a supporting frame of a liquid crystal display device.
2. Description of the Prior Art
As semiconductor fabrication technologies are rapidly advanced, display devices are required to be lighter, smaller and slimmer. This is especially the true for flat panel display devices such as liquid crystal displays and plasma displays. Therefore, the industry endeavors in reducing the number of assembly elements and in simplifying the process to the greatest extent possible.
LCD monitors are widely used for desktop computers and notebook computers. A LCD panel module and a backlight module are respectively assembled using separate assembly processes before both are assembled together. FIG. 1 is a disassembled perspective view of an upper frame 100 and a supporting frame 200 used in the conventional backlight module. The components of the liquid crystal display device such as a reflecting plate, a light guiding plate, a diffusing film and a lamp assembly are assembled together between the upper frame 100 with a central opening and the supporting frame 200, and the LCD panel is disposed directly contacting the upper side of the upper frame 100. There are several engaging elements 101 on the edges of the upper frame 100 to couple with counterparts 201 on the edges of the supporting frame 200 so that the upper frame 100 and supporting frame 200 are fastened and secured. Making liquid crystal display devices lighter and slimmer causes the upper frame 100 to be made very soft and results in the difficulty of mold injection. The assembly also becomes more complicated. To improve the fabrication process, U.S. Pat. No. 6,502,945B2 discloses a stack type backlight module and an assembly method thereof. The stack type backlight module includes a mold frame, a reflecting plate, a light guiding plate placed on the reflecting plate, a pair of lamp assemblies respectively accommodated at each side of the light guiding plate, diffusing plates placed on the light guiding plate and a pair of fixing frames facing each other covering the edge of the light guiding plate also detachably coupled to the mold frame.
U.S. Pat. No. 6,502,945B2 utilizes two L-shaped mold frames and a supporting frame to serve as a support for assembling other components. The L-shaped mold frames are coupled with the supporting frame to fasten the other components. The L-shaped mold frames need sufficient width to firmly support the LCD panel disposed on it. This reduces the view field of the liquid crystal display panel, and increasing the overall size and weight of the backlight module. Hence, it is necessary to provide an assembling method, which can utilize mold frames with narrower edge to firmly support and secure the stack type backlight assembly. The process for narrowing down the edge of the mold frame is called “edge-narrowing”.
Additionally, to save the material of the mold frame and reduce the cost of assembling the backlight module, another side mold frame is provided. The side mold frame is provided with a groove for containing the liquid crystal display panel and the backlight module. The side mold frame is also provided with engaging means for coupling and securing with the supporting frame. The side mold frame supports and secures the whole stack backlight module by means of the grooves and the engaging means. The materials needed for producing the side mold frame is less than that of the known upper frame 100. However, to attain a good securing effect, the edge of the side mold frame can not be made too narrow; otherwise, the good securing effect can not be provided. To meet the requirement for making the size of the liquid crystal display panels larger, the securing effect provided by the coupling strength of the groove of the side mold frame becomes worse. The resistant force of the side mold frame against the external torque becomes smaller, and resulting in the side mold frame to be easily detached from the stack type backlight module. Hence, the securing strength of the side mold frame is still not enough, and the view field size of liquid crystal devices with the side mold frame is less than that of devices with the upper frame 100.
To overcome the above drawbacks, the present invention is created.